update gemspec

Author: quinna-h

Diff for: datadog.gemspec

@@ -44,6 +44,8 @@ Gem::Specification.new do |spec|
       bin/**/*
       ext/**/*
       lib/**/*
+      gem_output.json
+      integration_versions.md
     ]]
       .select { |fn| File.file?(fn) } # We don't want directories, only files
       .reject { |fn| fn.end_with?('.so', '.bundle') } # Exclude local profiler binary artifacts